The present invention concerns a tracheostomy cannula comprising a cannula tube, wherein the cannula tube has a bend with a radially inward and a radially outward side of the cannula tube and a tube lumen and a tube wall and an axis extending parallel to the tube wall in the tube lumen and a distal and a proximal end and a first window region having one or more openings in the tube wall.
Patients having a tracheostoma, in whom the larynx is partially or completely preserved, are generally capable of talking. It will be noted however that for that purpose air must pass from the trachea upon exhalation into the region of the larynx. That is not possible in the case of tracheostomy cannulas having a closed cannula tube as the air passes through the cannula tube exclusively into the trachea, the bronchial tubes and the lungs and back in the same way.
In order nonetheless to permit patients with a larynx to talk, tracheostomy cannulas are used, in which the cannula tube has a window region. In that region the tube wall of the cannula tube is apertured by one or more openings. If during the exhalation process the tube lumen of the cannula tube is closed at the proximal end by a valve or by being covered with a finger, the exhaled air cannot escape through the proximal end of the tracheostomy cannula but passes through the window region to the larynx so that the patient can talk.
In that respect the terms ‘distal’ and ‘proximal’ are used from the point of view of a physician performing treatment, that is to say the proximal end of the tracheostomy cannula or the cannula tube is outside the body of the patient while in the inserted condition of the tracheostomy cannula the distal end is in the interior of the trachea.
Although tracheostomy cannulas are generally individually selected, it can happen due to slipping upon movement or a change in the anatomical conditions, for example due to the wound healing, that the window region is not free in the trachea but bears against the trachea wall or surrounding tissue. In those cases the patient cannot speak or can speak only with a very great effort. In addition particularly in the case of freshly operated patients there is the risk that the window region comes to lie in the stoma region and air passes into the tissue, resulting in the formation of emphysemas.
To resolve that problem, it has already been proposed in DE 10 2006 035 887 that a tracheostomy cannula is inserted, the effective length of the external cannula and/or the internal cannula of which is variable. By using such tracheostomy cannulas it is possible to position the window region of the cannula in such a way that the position is optimally adapted to the respective anatomical conditions.